the present invention relates to a vane pump which is one of pumps used for discharges, compressors, etc.
A vane pump schematically shown in FIG. 6 which has been heretofore widely known.
In FIG. 6, reference numeral 31 designates a house; 32 a rotor inserted eccentrically into a inner peripheral space of the housing 31 and rotatably supported by a rotational shaft 33; 35a, 35b and 35c, plate-like vanes disposed radially retractably from vane grooves 34a, 34b and 34c equally spaced apart so as to peripherally divide the outer peripheral side of the rotor 32 into three sections. When the rotor 32 is rotated in the direction as indicated by the arrow X by the rotational shaft 33, the vanes 35a, 35b and 35c are moved out in the direction of the outside diameter by the centrifugal force, and the end edges thereof rotate while slidably contacting the inner peripheral surface of the housing 31. Since the rotor 32 is eccentric with respect to the housing 31 as previously mentioned, as such rotation occurs, volumes of working spaces 36a, 36b and 36c defined by the housing 31, the rotor 3Z and the vanes 35a, 35b and 35c are repeatedly enlarged and contracted to allow a fluid taken in from the intake port 37 to be discharged out of an outlet port 38.
However, the above-described conventional vane pump has problems that since the vanes slidably move along the inner peripheral surface of the housing at high speeds, the lowering of the rotational efficiency due to the sliding resistance between the end edges of the vanes and the Inner peripheral surfaces of the housing cannot be avoided; the lowering of the volume efficiency of carrier fluid due to the sliding heat cannot be avoided; the vanes are expanded to produce galling with the both inner surfaces in the radial direction of the housing; and considerable wears occur.
In view of these problems, the present invention has been achieved in an attempt of preventing occurrence of resistance or generation of heat due to the sliding movement to enhance the efficiency in said rotation and volume.